This paper reports on an interpretive study of block play in a class of 16 kindergartners. Over the course of a school year 16 hours of videotape of the children's block play was recorded and analyzed. A typology of block play with four domains of block construction, social interaction, negotiation, and scheme development is explained and discussed. Data from the study indicate that young children arrive at school with a wealth of prior knowledge which is vastly more complex than the suggested kindergarten course of study found in public schools. The study suggests that there are at least two different agendas at work in the classroom, one usually associated with the classroom teacher, whose primary concern is directing the curriculum and instruction, and another associated with the children, whose main concern revolves around social interaction and construction of personally relevant knowledge. (MDM)